Reference is made to the German Patent Application 199 18 442.9-52 from which the present application claims priority.
This invention relates to an automatic stainer for staining objects, arranged on slides, for microscopic examination, in which multiple reagent containers arranged one behind another are provided for treating the objects, and the objects pass through the reagent containers in succession, having a transport basket for receiving multiple slides, such that multiple transport baskets can be received simultaneously in respective different reagent containers and the transport baskets are simultaneously lifted out of the respective reagent container by way of a motorized transport mechanism having a lifting device, and are transported on, one step in each case, into an adjacent reagent container.
After being cut on a microtome, the histological objects provided for microscopic examination are placed onto slides. The slides are then correspondingly labeled and catalogued. To increase the contrast for a subsequent microscopic examination, these objects are stained, making the structures in the cells or the tissue visible in differentiated fashion. In addition to various special stains, a standard staining process has proven successful in practice. With this H. E. stain, the specimens pass through various processing steps with xylene, alcohol, eosin, hematoxylin, acetic acid, and water. Various types of automatic stainers, which convey the specimens automatically to the respective processing steps, are used to stain the objects. The automatic stainers differ in terms of their mechanical construction and their manner of operation.
DE 36 34 976 C2 discloses an automatic stainer having a plurality of reagent containers, arranged next to and behind one another, in which the slides are arranged in preparation holders and are transported by a transport apparatus to the various containers. With this stainer, different staining programs can be performed simultaneously. For that purpose, the preparation holder can be introduced individually via the transport apparatus, using a gripping and positioning apparatus configured as a xe2x80x9cgantry crane,xe2x80x9d into any desired container, where it is uncoupled from the transport apparatus. With this transport apparatus, only a single preparation holder can be moved at one time. This results in only a low throughput of objects.
A further automatic stainer of two-row configuration, having reagent containers arranged one behind another, is known from DE 41 17 831 C2. Here as well, the preparation holders are transported individually to the various containers where they are uncoupled again from the transport apparatus. Here as well, multiple staining processes can be performed individually at the same time, but also with the disadvantage that only a relatively low throughput is possible.
An automatic stainer for the H.E. staining method with elevated throughput is described in U.S. Pat. No. 4,911,098. The stainer has multiple reagent containers arranged one behind another, into which the objects, arranged in preparation holders, are introduced via a transporting and gripping apparatus. After introduction, here as well the preparation holders are uncoupled from the gripping apparatus. An elevated throughput is achieved by the fact that multiple transporting and gripper apparatuses can be present simultaneously in the automatic stainer. The arrangement of multiple transporting and gripping apparatuses is of course associated with a very high level of complexity.
Further automatic stainers having a simplified transport mechanism and a high preparation throughput are offered by the company styled xe2x80x9cmeditexe2x80x9d under the name xe2x80x9cCOT 20,xe2x80x9d and by the company styled xe2x80x9cSakuraxe2x80x9d under the name xe2x80x9cLinear Slide Stainer II.xe2x80x9d Both automatic stainers operate on the principle of a continuously returning transport movement for the transport baskets in which the slides with the objects are located. In the course of the transport movement, the transport baskets are transported at constant cycling rates into the reagent containers arranged one behind another. A requisite residence time for the objects in the respective containers is achieved by way of multiple reagent containers arranged one behind another. The transport basket is suspended in a transport bar, and conveyed a specific distance by the transport bar to the next reagent container where it is lowered again. The transport bar travels back, under the supporting clip of the transport basket, into its initial position. A further transport basket can now be placed on the transport bar. Once a predefined cycle time has elapsed, the transport bar simultaneously lifts up all the transport baskets present in the automatic stainer and transports them into the next reagent container. At the last reagent container, a sensor is provided that is triggered by the transport basket and triggers a corresponding signal. The process is then continued until the corresponding transport basket is removed. It is disadvantageous in this case that the automatic stainer must be continuously monitored, since otherwise the specimens remain too long in the respective reagent containers and become unusable.
In practice, these automatic stainers are discontinuously loaded, so that gaps or unused cycle times exist between the individual transport baskets or a group thereof. The operator must therefore continuously ensure that the transport baskets are removed at the correct time.
It is therefore the object of the present invention to create a greater flexibility in the monitoring of an automatic stainer of this kind, and at the same time to simplify the removal of transport baskets.
According to the present invention, this object is achieved by the features recited in the characterizing portion of claim 1. Further advantageous developments are the subject matter of the dependent claims.
The automatic stainer is characterized in that a removal station having a collecting reagent container for the stained objects is arranged at the end of the row of reagent containers. This collecting reagent container is configured such that multiple transport baskets can be received simultaneously. The temporal sequence in which the transport baskets arrive in the collecting container is also immaterial in this context. Even long time intervals or cycle times between the individual incoming transport baskets are possible, with no need for intervention by an operator. Transport is interrupted only when the collecting container is completely filled with transport baskets. In addition, this collecting container is preferably filled with xylene or another corresponding liquid. Objects that have already been processed are thereby prevented from drying out and becoming unusable for subsequent microscopic examination.
In an embodiment of the invention, provision is made for the lifting device to be equipped, in the region of the collecting reagent container, with a stepped profile. The result of this is that the transport baskets are lifted up only slightly, and are transported on in steps into the collecting reagent container until an end stop limits further transport. The drive system is not stopped at this time. This is made possible by the stepped profile on the slide bar. The transport basket is merely lifted a short distance by the lifting device, and transported on. If the transport basket encounters, in this context, an end stop or another transport basket, the slide bar merely slides along on the transport basket. This ensures that the transport baskets become lined up one behind another in the collecting reagent container.
In a further embodiment of the invention, provision is made for the removal station to have a sensor arranged opposite the end stop. This sensor becomes active only when the collecting reagent container is completely filled with transport baskets.
The removal station has at least one ramp over which the transport baskets slide into the collecting reagent container and by way of which the sensor can be triggered. For that purpose, a spring-loaded lever is associated with the ramp. When a transport basket is delivered onto the ramp, the lever is moved and triggers the sensor. At the same time, the transport basket slides on the ramp completely into the collecting reagent container. This cancels the sensor signal again. Only when the collecting container is completely filled with transport baskets is it impossible for any further baskets to slide over the ramp, and the sensor remains activated.
In a further embodiment of the invention, the control circuit connected to the sensor is equipped with a time-delay logic system. This logic system ensures that corresponding optical and/or acoustic signals and/or signals for the transport mechanism are emitted only if the sensor signal is present uninterruptedly for a certain time.
In an advantageous embodiment, the sensor is configured as a completely encapsulated proximity sensor, so that no aggressive liquids or vapors can penetrate into the sensor and damage it.
Advantageously, the removal station is configured as a separate and retrofittable module.